Image forming apparatus

Abstract

An image forming apparatus includes a photosensitive drum, a charging member, a developing member, a transfer member, a brush, a drive unit, a control unit, and a memory. The charging member charges a surface of the photosensitive drum at a charging portion. The transfer member comes into contact with the photosensitive drum to form a transfer portion. The drive unit rotatably drive the photosensitive drum. The control unit controls the drive unit to perform an image forming operation. The memory stores information about the image forming operation. In a case where the image forming operation is performed and a non-image forming operation is performed after the image forming operation, the control unit performs control such that a switching operation for stopping the photosensitive drum after the photosensitive drum is driven and re-driving the photosensitive drum is performed a plurality of times based on the information about the image forming operation.

What is claimed is: 
     
       1. An image forming apparatus comprising:
 a photosensitive drum that is rotatable; 
 a charging member configured to charge a surface of the photosensitive drum at a charging portion; 
 a developing member configured to supply toner onto the surface of the photosensitive drum charged by the charging member; 
 a transfer member configured to come into contact with the photosensitive drum to form a transfer portion, and transfer the toner supplied onto the photosensitive drum to a transfer material at the transfer portion; 
 a brush configured to come into contact with the surface of the photosensitive drum downstream of the transfer portion and upstream of the charging portion in a rotational direction of the photosensitive drum; 
 a drive unit configured to rotatably drive the photosensitive drum; 
 a control unit configured to control the drive unit to perform an image forming operation; and 
 a memory configured to store information about the image forming operation, 
 wherein, in a case where the image forming operation is performed and a non-image forming operation is performed after the image forming operation, the control unit performs control such that a switching operation for stopping the photosensitive drum after the photosensitive drum is driven and re-driving the photosensitive drum is performed a plurality of times based on the information about the image forming operation, and 
 wherein, in a case where the switching operation is performed, the control unit controls the brush to change in orientation to a first orientation when the photosensitive drum is driven and a second orientation when the photosensitive drum is stopped. 
 
     
     
       2. The image forming apparatus according to  claim 1 , wherein, in a case where a first image forming operation and a second image forming operation to be performed after the first image forming operation are performed as the image forming operation and the non-image forming operation is performed between the first image forming operation and the second image forming operation, the control unit performs control such that the switching operation for stopping the photosensitive drum after the photosensitive drum is driven and re-driving the photosensitive drum is performed the plurality of times based on the information about the image forming operation. 
     
     
       3. The image forming apparatus according to  claim 1 , wherein the brush is a brush fixedly disposed on a supporting member of the photosensitive drum, or is a pressure brush applied with a predetermined pressure to be pressed against the photosensitive drum by a pressurizing spring. 
     
     
       4. The image forming apparatus according to  claim 1 ,
 wherein the information about the image forming operation is a number of continuously fed sheets in a case where a plurality of recording materials is fed in succession, and 
 wherein a number of times of the switching operations increases as the number of continuously fed sheets increases. 
 
     
     
       5. The image forming apparatus according to  claim 1 ,
 wherein the information about the image forming operation is a total number of sheets fed by the image forming apparatus, and 
 wherein a number of times of the switching operations increases as the total number of fed sheets increases. 
 
     
     
       6. The image forming apparatus according to  claim 1 , further comprising a brush voltage power source configured to apply a voltage to the brush,
 wherein the brush is a conductive brush, and 
 wherein, in a case where the switching operation is performed, the control unit controls the brush voltage power source to apply the voltage to the conductive brush. 
 
     
     
       7. The image forming apparatus according to  claim 1 , wherein the toner is a one-component developer. 
     
     
       8. The image forming apparatus according to  claim 1 , wherein the charging member is configured to come into contact with the surface of the photosensitive drum to form the charging portion. 
     
     
       9. The image forming apparatus according to  claim 1 , wherein the brush has a density of 150 kF/inch 2  or more.